The present invention is directed to apparatus for delivering aerosol medicament to a subject in need of the medicament. Delivery systems start with an aerosol-generating device. One common example of such devices is a pressurized metered dose inhaler (MDI). MDIs use pressurized gases to disperse medicament as tiny particles or droplets for delivery to the subject. By depressing the MDI, a known quantity of gas, and thereby of medicament, is ejected from the MDI. MDIs have been used with various types of diverse apparatus, in attempts to improve the delivery of this known quantity of medicament to the subject. Some problems associated with the delivery of medicament in an aerosol form include, but are not limited to, wastage of medicament in the delivery apparatus, delivery at too high speeds so that medicament sticks to the back of the subject's throat or is inhaled into the subject's sinuses rather than being received into the lungs, ejection of medicament out of the apparatus towards a subject without inhalation thereby, and ejection of medicament from the MDI upon exhalation by the subject into the apparatus prior to inhalation.